Brown bears from the Iberian Peninsula are not as genetically
different from other brown bears in Europe as was previously thought.
An international study being published this week in Proceedings of the
National Academy of Sciences, PNAS, shows that, on the contrary, the
Spanish bear was only recently isolated from other European strains.
These findings shed new light on the discussion of how to save the
population of Spanish bears.

The researchers extracted DNA and
determined the gene sequence of bears from prehistoric material,
primarily from the Iberian Peninsula. Some of the material was as much
as 80,000 years old. When the data material was analyzed, what emerged
was a totally unexpected pattern.

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“We expected to be able to
follow the Spanish brown bear far back in time, but we found to our
amazement that it had genetic material from bears in other parts of
Europe. In fact, it seems that the Spanish bear was isolated for the
first time in our own time,”Ě says doctoral student Cristina Valdiosera,
who performed most of the laboratory and analytical work.

“These
bears have possibly been isolated in Spain for a few thousand years,
which is a very short period in an evolutionary perspective. In other
words, there has been a flow of genes to and from the Iberian Peninsula
throughout most of the time brown bears have been there. This is
extremely interesting data when we discuss transporting bears from
other areas to Spain for the purpose of preservation,”Ě says Anders
G√∂therstam, who directed the study.

The number of bears on the
Iberian Peninsula is limited, with the population divided into two
small groups in the north. In-breeding and genetic depletion
constitutes a serious threat to the bears’ survival in this area. For
preservation purposes, the possibility of introducing bears from other
areas to the Iberian Peninsula has been discussed, but it has been
objected that this would entail the extinction of the genetically
unique Iberian bear. It has also been feared that bears from other
areas are not as well adapted to the living conditions on the Iberian
Peninsula as the Spanish bears are.

“But since there has never
been a genetically isolated brown bear on the Iberian Peninsula until
very recently, these arguments can be questioned,”Ě says Anders
G√∂therstam.